Closure for tank apertures



July 5, 1932- v. c. NoRQuls-r 1,865,538

CLOSURE FOR TANK APERTURES Filed May 20, 1931 'lgltfented July 5, 1932 UNITED STATES PATENT OFFICE VICTOR C. NORQ'UIST, OF KANSAS CITY, MISSOURI, ASSIGNOR T0 BUTLER MANUFAC- TURING-COMPANY, OF KANSAS CITY, MISSOURI, A CORPORATION OF MISSOURI CLOSURE FOR TANK APERTURES Application led May 20, 1931. Serial No. 538,770.

This invention relates to improvements in closures for tank apertures and refers more particularly to a quick operating closure for hand hole covers or manhole plates, such as are used in tanks or metal containers of any kind.

The invention is particularly adapted to the fill opening for truck tanks and affords a closure or cover equipped with a pressure tight, quick operating release to replace the screw closures now in common use.

In the drawing the invention is shown applied to the iill for an expansion dome of a truck tank, but this application has been chosen merely to disclose one application, it being understood that the closure may be used as well on any type of tank or container where it is an advantage to have a pressure tight closure which can be instantly removed or replaced.

Referring to the drawing, Fig. 1 is a sectional side view of a tank dome with the closure applied thereto.

Fig. 2 is a view taken along the line 2-2 in Fig. 1 in the direction of the arrows with a portion of the showing broken away.

In the top of a tank 1 is welded a dome 2, the lower portion of the dome extending a short distance into the tank. A manhole-3 serves as a closure for the top of the dome and is gasketed as shown at 4. Beneath the man* holes are a plurality of lugs 5 to which are attached the eyebolts 6. On the threaded ends of the eyebolts are clamps 7 which are formed to engage the lower rim of the dome 2. These clamps are held in position and drawn up by means of wing nuts 8. The manhole is usually equipped with a gasketed safety pressure relief cover 9, held in place by means of a fuse plug 10 positioned between the head 11 of a screw bolt 12 and a gasket 13 in the cover 9. The screw bolt 12 is held in position by means of lock nuts 14 and 15. A fire screen 16 is positioned below the pressure relief cover 9. This pressure relief arrangement is conventional equipment and forms no part of the present invention. Also in the top of the manhole 3 is an aperture or hand hole which is normally used as the ll. This aperture is closed by means of a cover plate 17, which is gasketed as shown at 17 a. At the axis of the cover is formed a well in which is positioned a pin 18. In the upper portion of the pin, the diameter is reduced by machiningr to form a cap 18a and beneath this cap is positioned a gasket 19 which fits into the top of the cover. The lower portion of the pin is also reduced by machining as shown at 186 and, around this portion of the pin, is a compression spring' 20. Pivoted to a lug 21 on the top of the cover plate 17 is a cam lever 22. The cam 23 contacts the top of the pin 18 and causes reciprocation of the pin 1n the well of the cover. A drilled lug 24 registers with a similar lug 25 on the cover 17 when the cam lever is rotated to hold the cover in a closed position. Beneath the cover 17 are a plurality of lugs 26 to which are pivoted dogs 27. The inner ends of the dogs contact the lower end of the pin 18, while the outer ends of these dogs are hook shaped as shown at 27a to engage the inside edge of the hand hole or fill aperture. This lower edge of the fill is preferably formed to offer a gripping edge for the ends of the dogs. In small wells drilled beneath the cover 17 are held compression springs 28. These compression springs Contact shoulders on thedogs and impose a constant spring tension upon the dogs tending to rotate them on their pivots. The tension of the springs 28 keeps the inner ends of the dogs in constant contact with the pin 18 so that the pin is maintained at all times in contact with the cam 23 of the lever 22.

In operation the lever 22 is swung to the dottedl line position shown in Fig. 1 at which time the. gripping ends 27a of the dogs are released from the inner edge of the aperture due to the compression springs 28. The closure 17 may be then removed from the hole or aperture in the manhole cover. This closure is removed when it is desired to tighten the wing nuts 8 and draw the manhole cover into pressure tight engagement with the expansion dome. After the manhole cover 3 has been drawn into pressure tight engagement with the dome, the gasketed closure 17 is placed upon the ring surrounding the aperture. I/Vhen placing the closure over the aperture, the cam lever is in a dotted line position as shown in Fig. 1. When the closure has been adjusted over the aperture or hand hole, the lever 22 is rotated on its pivot and due to the operation of the cam 23 depressing the pin 18, the dogs 27 Will engage the inside edge of the aperture tightly and uniformly gripping the edge at evenly spaced apart portions about the circumference of the hole. and drawing down the cover against the gasket to produce a pressure tight joint. Vhen the lever has been rotated to the full line position in Fig. 1, it may be padlocked through the registering holes of the engaging lugs 24 and 25. To remove the cover it is necessary only to remove. the padlock and throw back the lever 22 to the dotted line position, at which time the cover is free to be removed from the aperture which is covers.

The device oifers a closure for apertures in tanks or containers of any kind and in addition to the quick releasing feature assures a pressure tight engagement between the cover and container which is not assured by a screw joint. The gaskets shown may be of any suitable material according to the materials, either liquid or vapor, contained in the tank. Such materials as rubber, asbestos fibre, lead or other soft or resilient materials are usable according to the fluids to be restricted Within the container.

The function of the spring 20 is to serve as an adjustment for lost motion in the dogs, pin and cam connections and the Wear or difference in size of the gasket beneath the cover 17.

I claim as my invention:

1. A pressure tight closure for an aperture in a container comprising a cover having a movable pin therein, elements pivoted beneath the cover having one of their ends contacted by the pin and the opposite end adapted to grip the container, a cam lever pivoted on the cover, said lever adapted to reciprocate the pin and manipulate the pivoted elements to grip or release the container.

2. A pressure tight closure for an aperture in a container comprising a gasketed cover having a movable axial pin mounted therein, a cam lever on the cover, pivoted dogs beneath the cover having one of their ends contacted by the pin and their opposite ends adapted to grip and release the inside edges of the aperture With the manipulation of the cam lever.

VICTOR C. NORQUIST. 

